Electronic device for performing ranging by using ultra-wide band and operation method thereof

ABSTRACT

A method of a first device which performs ranging by using an ultra-wide band (UWB) and the first device are provided. The method of the first device includes performing ranging with a second device in a first ranging round among a plurality of ranging rounds included in a first ranging block, determining whether to perform hopping, based on a result of the performing of the ranging, when it is determined to perform the hopping, determining an index of a second ranging round for performing ranging with a second device, based on a random-number generation function, and performing the ranging with the second device in the second ranging round of a second ranging block.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is based on and claims priority under 35 U.S.C. §119(a) of a Korean patent application number 10-2019-0161838, filed onDec. 6, 2019, in the Korean Intellectual Property Office, the disclosureof which is incorporated by reference herein in its entirety.

BACKGROUND 1. Field

The disclosure relates to an electronic device for performing ranging byusing an ultra-wide band (UWB) communication technology and an operationmethod thereof

2. Description of Related Art

The Internet is evolving from a human-centered connection network viawhich humans create and consume information to an Internet-of-Things(IoT) network via which information is exchanged and processed betweendistributed components, such as things. Internet-of-Everything (IoE)technology is also emerging, in which big data processing technology iscombined with IoT technology via a cloud server or the like. Toimplement IoT, technical elements, such as detection technology,wired/wireless communication and network infrastructures, serviceinterface technology, and security technology, are required. In recentyears, research has been conducted on technologies, such as a sensornetwork, Machine-to-Machine (M2M), and machine-type communication (MTC),for connection between things.

In an IoT environment, intelligent Internet technology (IT) services maybe provided to collect and analyze data obtained from connected objectsto create new value in human life. As existing information technology(IT) and various industries converge and are combined with each other,IoT is applicable to the fields of smart homes, smart buildings, smartcities, smart cars or connected cars, smart grids, health care, smarthome appliances, advanced medical services, or the like.

With the development of wireless communication systems, various servicescan be provided and thus, there is demand for a method of effectivelyproviding such services. For example, a ranging technique for measuringthe distance between electronic devices by using an ultra-wideband (UWB)may be used for medium access control (MAC). The UWB is a radiocommunication technology that uses a very wide frequency band of severalgigahertz (GHz) or more in a base band without using a radio carrier.

The above information is presented as background information only toassist with an understanding of the disclosure. No determination hasbeen made, and no assertion is made, as to whether any of the abovemight be applicable as prior art with regard to the disclosure.

SUMMARY

Aspects of the disclosure are to address at least the above-mentionedproblems and/or disadvantages and to provide at least the advantagesdescribed below. Accordingly, an aspect of the disclosure is to providea hopping sequence for ultra-wide band (UWB) ranging.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments.

In accordance with an aspect of the disclosure, a method of a firstdevice which performs ranging by using an ultra-wide band (UWB) isprovided. The method of operating the first device includes performingranging with a second device in a first ranging round among a pluralityof ranging rounds included in a first ranging block, determining whetherto perform hopping, based on a result of performing ranging, when it isdetermined to perform hopping, determining an index of a second ranginground for performing ranging with a second device, based on arandom-number generation function, and performing ranging with thesecond device in a second ranging round of a second ranging block,wherein an index of the first ranging round and the index of the secondranging round may be different values.

In accordance with another aspect of the disclosure, a method of asecond device which performs ranging by using an UWB is provided. Themethod of operating the second device includes performing ranging with afirst device in a first ranging round among a plurality of rangingrounds included in a first ranging block, determining whether to performhopping, based on at least one of a result of performing ranging orinformation about a ranging round received from the first device, whenit is determined to perform hopping, determining an index of a secondranging round for performing ranging with the first device, based on arandom-number generation function, and performing ranging with the firstdevice in a second ranging round of a second ranging block. An index ofthe first ranging round and the index of the second ranging round may bedifferent values.

Other aspects, advantages, and salient features of the disclosure willbecome apparent to those skilled in the art from the following detaileddescription, which, taken in conjunction with the annexed drawings,discloses various embodiments of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of certainembodiments of the disclosure will be more apparent from the followingdescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a diagram illustrating a general device-to-device (D2D)communication procedure according to an embodiment of the disclosure;

FIG. 2 is a diagram illustrating a process of communication between aplurality of electronic devices according to an embodiment of thedisclosure;

FIG. 3 illustrates examples of a single-sided two-way ranging (SS-TWR)using a ranging control frame according to an embodiment of thedisclosure;

FIG. 4 illustrates a configuration of a ranging block according to anembodiment of the disclosure;

FIG. 5 is a diagram illustrating a block-based mode according to anembodiment of the disclosure;

FIG. 6 is a timing diagram of a block-based mode according to anembodiment of the disclosure;

FIG. 7 is a diagram illustrating ranging slots to which differenttransmission offsets are allocated according to an embodiment of thedisclosure;

FIG. 8 is a diagram illustrating hopping in ranging according to anembodiment of the disclosure;

FIGS. 9A and 9B are diagrams illustrating a concept of a transmissionoffset and round hopping according to various embodiments of thedisclosure;

FIG. 10 is a flowchart of an operation method of a first device whichperforms ranging by using an ultra-wide band (UWB) according to anembodiment of the disclosure;

FIG. 11 is a table illustrating subsequent ranging rounds derived basedon a random-number generation function according to an embodiment of thedisclosure;

FIG. 12 is a diagram illustrating a configuration of information aboutranging control according to an embodiment of the disclosure;

FIG. 13 is a diagram illustrating a configuration of information about aranging round according to an embodiment of the disclosure;

FIG. 14 is a flowchart of an operation method of a second device whichperforms ranging by using a UWB according to an embodiment of thedisclosure;

FIGS. 15A and 15B are diagrams illustrating a ranging success rate whenranging is performed according to an index of a determined hopping rangeround according to various embodiments of the disclosure;

FIGS. 16A and 16B are diagrams illustrating a ranging success rate whenranging is performed according to an index of a determined hopping rangeround according to various embodiments of the disclosure;

FIGS. 17A and 17B are diagrams illustrating a ranging success rate whenranging is performed according to an index of a determined hopping rangeround according to various embodiments of the disclosure;

FIG. 18 is a block diagram of a controller according to an embodiment ofthe disclosure;

FIG. 19 is a block diagram of a controllee according to an embodiment ofthe disclosure; and

FIG. 20 is a block diagram of an electronic device according to anembodiment of the disclosure.

Throughout the drawings, like reference numerals will be understood torefer to like parts, components, and structures.

DETAILED DESCRIPTION

The following description with reference to the accompanying drawings isprovided to assist in a comprehensive understanding of variousembodiments of the disclosure as defined by the claims and theirequivalents. It includes various specific details to assist in thatunderstanding but these are to be regarded as merely exemplary.Accordingly, those of ordinary skill in the art will recognize thatvarious changes and modifications of the various embodiments describedherein can be made without departing from the scope and spirit of thedisclosure. In addition, descriptions of well-known functions andconstructions may be omitted for clarity and conciseness.

The terms and words used in the following description and claims are notlimited to the bibliographical meanings, but, are merely used by theinventor to enable a clear and consistent understanding of thedisclosure. Accordingly, it should be apparent to those skilled in theart that the following description of various embodiments of thedisclosure is provided for illustration purpose only and not for thepurpose of limiting the disclosure as defined by the appended claims andtheir equivalents.

It is to be understood that the singular forms “a,” “an,” and “the”include plural referents unless the context clearly dictates otherwise.Thus, for example, reference to “a component surface” includes referenceto one or more of such surfaces.

In the disclosure, general terms that have been widely used nowadays areselected, based on functions of the disclosure but various other termsmay be selected according to the intentions of technicians in the art,precedents, or new technologies, or the like. Accordingly, the termsused herein should be defined not based on the names thereof but basedon the meanings thereof and the whole context of the disclosure.

Terms, such as first and second may be used to describe variouscomponents but the components should not be limited by the terms. Theseterms are only used to distinguish one component from another.

The terms used herein are for the purpose of describing certainembodiments of the disclosure only and are not intended to be limitingof the disclosure. As used herein, the singular expressions are intendedto include plural forms as well, unless the context clearly dictatesotherwise. Throughout the specification, when an element is referred toas being “connected” to another element, it will be understood toinclude that the element is “directly connected” to the other element oris “electrically connected” to the other element with another elementtherebetween. It will be understood that when an element is referred toas “including” another element, the element may further include otherelements unless mentioned otherwise.

Throughout the disclosure, the expression “at least one of a, b or c”indicates only a, only b, only c, both a and b, both a and c, both b andc, all of a, b, and c, or variations thereof.

Examples of a terminal may include a user equipment (UE), a mobilestation (MS), a cellular phone, a smartphone, a computer, a multimediasystem capable of performing a communication function, or the like.

In the disclosure, a controller may also be referred to as a processor.

Throughout the specification, a layer (or a layer apparatus) may also bereferred to as an entity.

As used herein, “the” and similar referents may be used to indicate bothsingular and plural forms. When there is no description explicitlyspecifying an order of operations of a method according to an embodimentof the disclosure, the operations may be performed in an appropriateorder. The disclosure is not limited to the order of the operationsdescribed.

The expression “in an embodiment” and the like appearing in variousparts of the specification are not intended to refer to the sameembodiment.

An embodiment of the disclosure may be represented by functional blockconfigurations and various operations. Some or all of the functionalblocks may be implemented by various numbers of hardware and/or softwareconfigurations for performing certain functions. For example, thefunctional blocks of the disclosure may be implemented by one or moremicroprocessors or by circuit configurations for a certain function. Forexample, the functional blocks of the disclosure may be implemented invarious programming or scripting languages. The functional blocks may beimplemented in an algorithm executed by one or more processors. In thedisclosure, the prior art may be employed for electronic configuration,signal processing, and/or data processing.

In addition, lines or members connecting elements illustrated in thedrawings are merely illustrative of functional connections and/orphysical or circuit connections. In an actual device, the connectionsbetween components may be represented by various functional connections,physical connections, or circuit connections that are replaceable oradded.

In general, wireless sensor network technology is largely classifiedinto wireless local area network (WLAN) and wireless personal areanetwork (WPAN) according to a distance identified. In this case, WLAN isan institute of electrical and electronics engineers (IEEE) 802.11-basedtechnology for connection to a backbone network within a radius of 100m. WPAN is a technology based on IEEE 802.15, and examples thereofinclude Bluetooth, ZigBee, ultra-wide band (UWB), and the like. Awireless network in which such wireless network technology isimplemented may include a plurality of communication electronic devices.In this case, the plurality of communication electronic devicesestablish communication in an active period using a single channel Forexample, the plurality of communication electronic devices may collectand transmit packets in the active period.

UWB may refer to a short-range high-speed radio communication technologyusing a wide frequency band of several GHz or more, low spectraldensity, and a short pulse width (1 to 4 nsec) in a baseband state. UWBmay be understood as a frequency band to which UWB communication isapplied. A ranging method performed between electronic devices will nowbe described based on a UWB communication method, but the UWBcommunication method is only an example and various radio communicationtechnologies may be used in practice.

Electronic devices according to embodiments of the disclosure mayinclude a fixed user equipment (UE) embodied as a computer device or amobile UE, and may communicate with other devices and/or servers using awireless or wired communication method. For example, the electronicdevices may include, but are not limited to, a smart phone, a mobileterminal, a laptop computer, a digital broadcasting terminal, a personaldigital assistant (PDA), a portable multimedia player (PMP), anavigation device, or a slate person Computer (PC), a tablet PC, adigital television (TV), a desktop computer, a refrigerator, aprojector, a car, a smart car, a printer, and the like.

Hereinafter, the disclosure will be described with reference to theaccompanying drawings.

FIG. 1 is a diagram illustrating a general device-to-device (D2D)communication procedure according to an embodiment of the disclosure.

D2D communication refers to a way in which geographically adjacentelectronic devices communicate directly with each other without via aninfrastructure, such as a base station.

Referring to FIG. 1, electronic devices may communicate in a one-to-onemanner, a one-to-many manner, or a many-to-many manner In D2Dcommunication, unlicensed frequency bands, such as wireless fidelity(Wi-Fi) Direct and Bluetooth may be used. Alternatively, in D2Dcommunication, licensed frequency bands may be used to improve frequencyutilization efficiency of cellular systems. Although D2D communicationis restrictively used to refer to M2M communication or machineintelligent communication, in the disclosure, D2D communication isintended to refer to not only communication between electronic deviceshaving a communication function but also communication between varioustypes of electronic devices having a communication function, such assmart phones or personal computers.

FIG. 2 is a diagram illustrating a process of communication between aplurality of electronic devices according to an embodiment of thedisclosure.

Referring to FIG. 2, a first electronic device 201 and a secondelectronic device 202 may establish communication through a devicediscovery process 203, a link generation process 204, and a datacommunication process 205.

In the device discovery process 203, each of the first electronic device201 and the second electronic device 202 may search for other electronicdevices capable of establishing D2D communication among neighboringelectronic devices. Thus, each of the first electronic device 201 andthe second electronic device 202 may determine whether to create a linkfor D2D communication. For example, the first electronic device 201 maytransmit a discovery signal to the second electronic device 202 so thatthe second electronic device 202 may search for the first electronicdevice 201. In addition, the first electronic device 201 may receive adiscovery signal transmitted from the second electronic device 202 toidentify that that other electronic devices capable of establishing D2Dcommunication are within a D2D communication range.

In the link generation process 204, each of the first electronic device201 and the second electronic device 202 may create a link for datatransmission with an electronic device, which is to transmit data, amongthe electronic devices searched for in the device discovery process 203.For example, the first electronic device 201 may create a link for datatransmission with the second electronic device 202 searched for in thedevice discovery process 203.

In the data communication process 205, each of the first electronicdevice 201 and the second electronic device 202 may transmit data to andreceive data from the devices for which the link for data transmissionis created in the link generation process 204. For example, the firstelectronic device 201 may transmit data to and receive data from thesecond electronic device 202 through the link created in the linkgeneration process 204.

Various embodiments of the disclosure relate to medium access control(MAC) based on D2D communication described above, and it is necessary tomeasure the distance between electronic devices for MAC. In this case,UWB ranging technology may be used to measure the distance betweenelectronic devices. For example, when a digital key stored in a smartphone is used to open or close the door of a vehicle, the vehicle maymeasure the distance between the smartphone and the vehicle by using anumber of UWB communication modules (e.g., six UWB communicationmodules) and estimate the location of the smart phone, based on a resultof the measurement. The vehicle and the smart phone are capable of usingmulticast ranging or broadcast ranging.

An electronic device according to an embodiment of the disclosure mayperform ranging using a ranging control frame. Two types of devicesrelated to ranging control may be referred to as a “controller 100” anda “controller 200”.

First, the controller 100 may be defined as a device that defines andcontrols ranging parameters by transmitting a ranging control frametogether with a ranging control information element (IE). The rangingcontrol frame is used to set ranging parameters.

The controllee 200 may be defined as a device that uses the rangingparameters received from the controller 100. At least one controllee 200may be managed by the controller 100. A method of determining a role ofa device (e.g., a role of a controller or a role of a controllee) andselecting ranging parameters may be implemented in various ways.

Two types of devices for ranging control may be referred to as an“initiator” and a “responder”. The initiator refers to a device thatstarts ranging by sending a poll. The responder refers to a device thatresponds to the poll received from the initiator.

The controller 100 according to an embodiment of the disclosure iscapable of determining devices to participate in ranging and devicetypes by using a ranging initiator/responder list (IRL) IE or a rangingscheduling (RS) IE. The IRL IE and the RS IE may be transmitted in aranging control frame. In the case of scheduling-based ranging, the RSIE may be configured by the controller 100 to manage resources andindicate roles of devices (i.e., a role of an initiator or a responder).The IRL IE may be used to determine roles of devices when the RS IE isnot used in the case of contention-based ranging.

A schedule mode field of the ranging control IE indicates whether aranging frame is transmitted using contention or a schedule. Devicesthat are not specified by such IEs cannot participate in ranging. Whentransmission of a poll frame by a device is required, a device type ofthe device may be determined as an initiator, whereas a deviceresponding to the poll frame may be determined as a responder.

In the case of contention-based multicast/broadcast ranging, thecontroller 100 may be the only initiator in ranging and prevent an IRLIE from being added to a ranging control frame when a responder isdesignated in a destination address field included in a MAC header ofthe ranging control frame.

Because the ranging control frame includes the IRL IE or the RS IE, thecontrollee 200 may identify whether a poll is to be transmitted byreceiving the ranging control frame. When a device type of thecontrollee 200 is designated as an initiator in the IRL IE or the RS IE,the controllee 200 may transmit a poll frame. Both the controller 100and control 200 may serve as initiators or responders.

FIG. 3 illustrates examples of a single-sided two-way ranging (SS-TWR)using a ranging control frame. SS-TWR is one of various ranging methodsintroduced according to an embodiment of the disclosure.

Referring to FIG. 3, when a controller 100 is set to transmit a pollframe as illustrated in a flowchart 301 of FIG. 3, the controller 100may serve as an initiator and transmit a poll frame. On the other hand,when a controllee 200 is set to transmit a poll frame as illustrated ina flow chart 302 of FIG. 3, the controllee 200 may serve as an initiatorand transmit a poll frame.

The ranging control frame may include a ranging acknowledgment IEindicating a ranging response type. A plurality of controllees may beused for multicast/broadcast/M2M ranging.

A device according to an embodiment of the disclosure may performranging in units of ranging blocks.

The ranging blocks each represent a virtual time frame for ranging. Theranging blocks each consist of several ranging rounds. Each of theranging rounds indicates completion of all ranging events betweenranging devices of a UWB network. The ranging rounds each consist ofseveral ranging slots. The ranging slots represent virtual time unitsfor transmission of a ranging frame. The ranging blocks, the rangingrounds, and the ranging slots are based on virtual times and thustime-based synchronization is not required therefor.

FIG. 4 illustrates a configuration of a ranging block according to anembodiment of the disclosure.

Referring to FIG. 4, a ranging block 410 may include N ranging rounds421, 422, 423, 424, and 425. The ranging round 421 may include M rangingslots 431, 432, 433, and 434.

A time unit (TU) is defined as a minimum MAC time operation in PHYunits. A ranging slot length is defined as an integral number of TUs.The ranging slot length is adjustable by a multiplier of a TU. The TU isfixed to 250 us which is an integer multiple of a reciprocal of achipping rate of 499.2 megahertz (MHz). A ranging round is defined as anintegral number of ranging slots. A duration of the ranging round isadjustable by a multiplier of a ranging slot. A ranging block length isdefined as an integer multiple of MinimumBlockLength. The ranging blocklength is adjustable by a multiplier of Minimumblocklength.MinimumBlockLength is defined as an integer number of TUs.

According to various embodiments of the disclosure, two types of rangingmodes (e.g., an interval-based mode ad a block-based mode) may be usedfor access control. A strict time structure is used in the block-basedmode but is not used in the interval mode. The controller 100 may selectone of modes and specify the selected mode by using a time structureindicator of a ranging control IE.

FIG. 5 is a diagram illustrating a block-based mode according to anembodiment of the disclosure.

Referring to FIG. 5, in the block-based mode, a ranging block structureusing a timeline, which is set at certain intervals of time, is used.

In the block-based mode, the ranging block structure may be determinedbased on a ranging block length field, a ranging round duration field,and a ranging slot length which are included in information aboutranging control. The information about ranging control will be describedwith reference to FIG. 12 below. Hereinafter, for convenience ofdescription, the information about ranging control will be referred toas a ranging control information element. In an embodiment of thedisclosure, the information about on ranging control may be an advancedranging control information element.

Equation 1 below is an equation for calculating a time duration from aranging round with an index ‘0’ of a ranging block with an index ‘0’ toa ranging round with an index ‘0’ of a ranging block with an index ‘1’in a k^(th) session.

UWB _(timne0) ^(k)(i, 0)=UWB _(time0) ^(k)(0, 0)+i×T _(Block) ^(k)i=1,2, . . .   Equation 1

Equation 2 below is an equation for deriving the number of rangingrounds included in a ranging block.

$\begin{matrix}{{{Number}\mspace{14mu} {of}\mspace{14mu} {Ranging}\mspace{14mu} {Rounds}} = \frac{{Ranging}\mspace{14mu} {Block}\mspace{14mu} {Duration}}{{Ranging}\mspace{14mu} {Round}\mspace{14mu} {Duration}}} & {{Equation}\mspace{14mu} 2}\end{matrix}$

Equation 3 below is an equation for deriving the number of ranging slotsincluded in a ranging round.

$\begin{matrix}{{{Number}\mspace{14mu} {of}\mspace{14mu} {Ranging}\mspace{14mu} {Slots}} = \frac{{Ranging}\mspace{14mu} {Round}\mspace{14mu} {Duration}}{{Ranging}\mspace{14mu} {Slot}\mspace{14mu} {Duration}}} & {{Equation}\mspace{14mu} 3}\end{matrix}$

When a device receives a ranging control message (RCM), the device mayset a structure of a ranging block and a related timeline for ranging byusing field values included in the ranging control information element.In another embodiment of the disclosure, the ranging block structure maybe set by a next higher layer.

A controller may repeatedly transmit the ranging block structure in allranging control messages. When the ranging block structure needs to bechanged or updated, the controller may transmit a ranging block updateIE (RBU IE) including fields related to updating of a ranging block.

Configurations of ranging blocks will be described with reference toFIGS. 4 and 5 below. Indexes of the ranging blocks may be set toincrease sequentially, based on a first ranging block. In this case, asone example, a block index of the first ranging block may be 0, andblock indexes of the ranging blocks may be set to increase by one.

Furthermore, indexes of ranging rounds in each of the ranging blocks maybe set to increase sequentially, based on the first ranging round in theranging block. For example, when M ranging rounds are included in aranging block, a ranging round index of a first ranging round of theranging block may be 0 and a ranging round index of a last ranging roundof the ranging block is M−1.

Referring to FIGS. 4 and 5, indexes of ranging slots in each ranginground may be set to increase sequentially, based on a first ranging slotin each ranging round. In this case, for example, a ranging round indexof the first ranging round may be 0. For example, when K ranging slotsare included in a ranging round, a ranging slot index of a first rangingslot of the ranging round may be 0 and a ranging slot index of a lastranging slot of the ranging round may be K−1.

In this case, for example, the controller may transmit a first rangingcontrol message in the first ranging slot (ranging slot index ‘0’) ofthe first ranging round (ranging round index ‘0’) included in the firstranging block (ranging block index ‘0’).

To perform a range message exchange in the first ranging round, thecontroller may transmit a ranging control message packet in the firstranging slot.

In this case, the ranging control message may include a ranging round IEfor signaling information about a ranging round of a current rangingblock. The ranging round IE will be described with reference to FIG. 13below.

FIG. 6 is a timing diagram of a block-based mode according to anembodiment of the disclosure.

Referring to FIG. 6, it illustrates a ranging round included in aranging block N. The ranging round includes several ranging slots. Aranging frame may be transmitted in the ranging slots. In addition, theranging frame may be transmitted in the ranging slots by setting atransmission offset.

FIG. 7 is a diagram illustrating ranging slots to which differenttransmission offsets are allocated according to an embodiment of thedisclosure.

Referring to FIG. 7, in subsequent ranging rounds, a controller maydetermine to start transmission within ranging slots to which differenttransmission offsets are assigned. In this case, the controller maytransmit, to a controllee, information about a transmission offsetthrough a transmission offset field included in a ranging round IE. Thetransmission offset should be smaller than a result of subtracting a UWBpacket duration from a duration of a ranging slot. The transmissionoffset may be expressed as a multiple of a ranging scheduling time unit(RSTU). All packets within the same ranging round should be transmittedwith the same transmission offset.

FIG. 8 is a diagram illustrating hopping in ranging according to anembodiment of the disclosure.

Hopping in UWB-based ranging may be understood to mean performingranging in a predetermined round when it is not appropriate to performranging in a ranging round that is in use between devices. In this case,for example, a hopping sequence for performing hopping may be previouslystored in the devices.

For convenience of description, it will be described in FIG. 8 thatRDEV1 represents a first device and RDEV2 represents a second device.

Referring to FIG. 8, in a 0^(th) block 800, the first device and thesecond device use a 0^(th) round 801 as a ranging round. In this case,the first device may perform ranging to the second device in the 0^(th)round 801. In this case, a present value of a hopping mode may be 0.

In this case, when the ranging between the first device and the seconddevice is successful in the 0^(th) round 801, the first device and thesecond device may continue to use the same ranging round in a subsequentranging block. For example, when a ranging round m is used in an n^(th)ranging block, the ranging round m may also be used in an (n+1)^(th)ranging block. Referring to FIG. 8, the first device and the seconddevice may perform ranging using the 0^(th) round 811 even in a firstblock 810.

Referring to FIG. 8, because the first device and the second device havesuccessfully performed ranging in the 0^(th) round 801, ranging is alsoperformed by the first block 810 by using the 0^(th) round 811. In thiscase, the first device cannot perform ranging to the second device inthe round 0 811. In this case, the value of the hopping mode may bechanged to 1.

As the first device changes the value of the hopping mode to 1 and thechanged value of the hopping mode is transmitted to the second device,the first device and the second device may perform hopping. For example,the first device may be a controller and the second device may be acontrollee. Ranging round hopping may be performed when the first deviceand the second device perform ranging in a second block 820.

In the second block 820, the first device and the second device mayperform ranging in a first round 822 instead of a 0^(th) round accordingto a result of hopping. For example, when the first device and thesecond device use the m^(th) ranging round m in the n^(th) rangingblock, a k^(th) ranging round may be used in the (n+1)^(th) rangingblock (k≠m). When ranging is successful in the first round 822, thevalue of the hopping mode may be changed to 0. As the first devicechanges the value of the hopping mode to 0 and the changed value of thehopping mode is transmitted to the second device, the first device andthe second device may perform ranging in a set ranging round. Therefore,referring to FIG. 8, even in a third block 830, ranging may be performedin a first round.

FIGS. 9A and 9B are diagrams illustrating a concept of a transmissionoffset and round hopping according to various embodiments of thedisclosure.

Referring to FIG. 9A, the same ranging round j and the same transmissionoffset s are used in a ranging block N and a ranging block (N+1).

Referring to FIG. 9B, a ranging round j is used in a ranging block N buta ranging round k is used in a ranging block (N+1) by hopping.Separately from hopping, in FIG. 9B, a transmission offset s is used inthe ranging block N but a transmission offset 0 is used in the rangingblock (N+1).

In a ranging round allocated to a ranging block, a controller mayconfigure the ranging round by transmitting a ranging control message(RCM) together with a ranging control IE and a ranging round IE. In thiscase, according to an embodiment of the disclosure, the ranging controlIE may have the same structure as a ranging IE illustrated in FIG. 12.According to an embodiment of the disclosure, the ranging round IE mayhave a structure as illustrated in FIG. 13. A higher layer of thecontroller may select at least one of a hopping mode or a transmissionoffset to be used in a ranging round of a subsequent ranging block

When the controller transmits to a controllee a final message scheduledin a current ranging round of a ranging block i, the controller maytransmit a ranging round IE in the final message in the current ranginground to signal whether to hop from a ranging round of a ranging block(i+1), which is a subsequent ranging block, to another round. Theranging round IE may include a ranging block index field and a ranginground index field of the current ranging block and a hopping mode fieldand a transmission offset field for a ranging round of the subsequentranging block. A more detailed description will be provided withreference to FIG. 13 below.

After the controllee receives the ranging round IE in the final messageof a ranging message sequence, a higher layer of the controllee may usean indicated ranging round in the subsequent ranging block.

When, due to an interference event, the controllee did not receive theranging round IE in the final message or the RCM, the controllee mayturn on a hopping mode in the subsequent ranging block. In this case,the controllee may perform ranging using a new ranging round determinedby a new hopping mode, a subsequent ranging block index, and a hoppingsequence.

FIG. 10 is a flowchart of an operation method of a first device whichperforms ranging by using a UWB according to an embodiment of thedisclosure.

Referring to FIG. 10, an operation method of each of the controller 100and the controllee 200 according to an embodiment of the disclosure willbe described below. When ranging is performed between two electronicdevices, one of the two electronic devices may serve as a controller andthe other may serve as a controllee. Thus, the controller may bereferred to as a first device and the controllee may be referred to as asecond device. Alternatively, one of the two electronic devices mayserve as an initiator and the other may serve as a responder.

As used herein, a ranging session may refer to a group of devicesinvolved in a continuous ranging procedure characterized by a certaininitial parameter set. The ranging session should include one controllerand one or more initiators. In this case, only the controller is capableof configuring initial ranging parameters. In addition, only thecontroller is capable of updating ranging parameters during a rangingsession.

As used herein, a first ranging block may refer to a current rangingblock in which a first device and a second device perform ranging orattempt ranging.

A second ranging block may refer to a ranging block after the firstranging block. For example, the first device and the second device mayperform ranging in the first ranging block and thereafter performranging in the second ranging block. The second ranging block may be aranging block immediately after the first ranging block. However, thesecond ranging block should be understood to means a ranging blockarriving after the first ranging block and is not limited to theabove-described example. As described above, the second ranging blockmay correspond to a ranging block index greater than that of the firstranging block.

As used herein, the first device and the second device may performranging in a first ranging round of the first ranging block. The firstranging round is a round in which ranging is currently performing andmay refer to a ranging round that is set before hopping. In this case,according to an embodiment of the disclosure, the first ranging roundmay correspond to an m^(th) ranging round included in the first rangingblock. According to the above example, when it is assumed that an indexof the first ranging round is 0, the first device and the second devicemay perform ranging in a ranging round corresponding to index (m−1) inthe first ranging block.

In the present specification, when hopping is performed, the firstdevice and the second device may perform ranging in a hopping round. Asecond ranging round may refer to a certain ranging round with respectto which hopping is performed and thus, it is determined that ranging isto be performed in the certain ranging block after the second rangingblock. In an embodiment of the disclosure, the second ranging round mayrefer to a k^(th) ranging round included in the second ranging block.According to the above example, when it is assumed that the index of thefirst ranging round is 0, the first device and the second device mayperform ranging in a ranging round corresponding to index (k−1) in thesecond ranging block. In this case, m and k are merely values providedas examples of different values. In addition, the index corresponding tothe first ranging round and the index corresponding to the secondranging round are different values.

According to an embodiment of the disclosure, the first device mayperform ranging with the second device, based on the block-based mode.

Referring to FIG. 10, in operation S1010, the first device may performranging with the second device in the first ranging round among aplurality of ranging rounds included in the first ranging block. In anembodiment of the disclosure, the first device may perform ranging withthe second device in an m^(th) ranging round among the plurality ofranging rounds included in the first ranging block.

As used herein, “perform ranging” may be understood to mean onlytransmission of a ranging frame RFRAME. For example, “perform ranging”should be understood to include a case in which ranging failed becausethe first device did not receive a response from the second device. Forexample, “perform ranging” does not refer to deriving a ranging resultvalue and should be understood to mean transmission of the ranging frameby a controller regardless of whether ranging fails or succeeds.

In operation S1020, the first device may determine whether to performhopping, based on a result of performing ranging.

In an embodiment of the disclosure, the determining of whether toperform hopping, based on the result of performing ranging, may includedetermining that hopping is to be performed when the first device doesnot receive a response from the second device in the first ranginground. In addition, when the first device receives a response from thesecond device in the first ranging round, it may be determined that thefirst ranging round, which is a preset ranging round, is to becontinuously used.

In another embodiment of the disclosure, the determining of whether toperform hopping, based on the result of performing ranging, may includedetermining, by the first device, that hopping is to be performed, basedon an interference level for the first ranging round. For example, inorder to determine whether it is appropriate to perform ranging for acurrent ranging round, the first device may identify whether aninterference level for the current ranging round is less than or equalto a reference value.

For example, when the interference level is less than or equal to thereference value, the first device may determine to continue to use thefirst ranging round that is a preset ranging round. As another example,when the interference level is greater than the reference value, thefirst device may determine to perform hopping.

In another embodiment of the disclosure, the first device may determineto trigger a hopping function, based on the number of responses receivedfrom the second device.

In operation S1030, when the first device determines to perform hopping,an index of a second ranging round for performing ranging with thesecond device may be determined, based on a random number generationfunction. In an embodiment of the disclosure, when the first devicedetermines to perform hopping, the index of a ranging round forperforming ranging with the second device may be changed to (k−1), basedon the random number generation function.

In an embodiment of the disclosure, the determining of the index of thesecond ranging round may include determining the index of the secondranging round, based on a result value of the random number generationfunction calculated based on an index corresponding to the secondranging block and a value of a hopping key of a ranging session.

In the present specification, the hopping key may be understood to meana key used when a hopping sequence is performed. In this case, thehopping key may be generated differently for each session createdbetween the first device and the second device. For example, a hoppingkey generated by the first device for a first session between the firstdevice and the second device and a hopping key generated by the firstdevice for a second session between the first device and the seconddevice may be the same or may be different from each other.Alternatively, the hopping key may be generated differently for eachpair of devices (hereinafter referred to as ‘pair’). More specifically,when the first device and the second device are defined as a first pairand a third device and a fourth device are defined as a second pair, ahopping key used for the first pair and a hopping key used for thesecond pair may be the same or may be different from each other. In thiscase, each of the hopping keys may be generated from an initiator andtransmitted to a responder. For explanation of the disclosure, theinitiator will be referred to as the first device and the responder isdescribed as the second device.

In an embodiment of the disclosure, the operation method may furtherinclude starting a ranging session between the first device and thesecond device and transmitting by the first device a hopping key for theranging session.

More specifically, first, a ranging session between the first device andthe second device may be started. Next, the second device may transmit aranging session request (RS-RQ) message to the first device. The firstdevice may transmit a ranging session response (RS-RS) message to thesecond device. When the exchange of the ranging session request messageand the ranging session response message between the first device andthe second device is successful, a ranging session may be establishedthrough a Bluetooth low energy (BLE) control channel

Thereafter, the second device may transmit a ranging session setuprequest (RSS-RQ) message to the first device. After receiving theranging session setup request message from the second device, the firstdevice may determine a structure of a ranging block for the rangingsession. More specifically, the first device may determine the number ofrounds for a block to be used in the ranging session. In addition, thefirst device may also determine a preamble synchronization (SYNC) codeindex. Thereafter, the first device may transmit a ranging session setupresponse (RSS-RS) message to the second device.

In an embodiment of the disclosure, the hopping key for the rangingsession may be transmitted in the ranging session setup response(RSS-RS) message transmitted by the first device to the second device.

In an embodiment of the disclosure, the random number generationfunction may include a hash function. When the hash function is used asthe random number generation function, the index ‘k’ may be determinedbased on a result value of the hash function for the sum of an indexcorresponding to the second ranging block and a value of the hopping keyfor the ranging session. The following equation shows a method ofdetermining the index of the second ranging round, which is a hoppedround, by using the hash function.

S(i, HoppingKey, N _(Round))=(((HASH(i+HoppingKey)&0xFFFF)N_(Round))»16)+1   Equation 4

Here, S represents the index of the second ranging round which is ahopped round. i may represent the index of the second ranging block. Forexample, i may represent an index corresponding to a ranging block inwhich hopping is performed. HoppingKey may represent the hopping keydescribed above. NRound may represent the number of ranging roundsincluded in the ranging block.

For example, the random number generation function may include at leastone of Advanced Encryption Standard 128 (AES128), Secure Hash Algorithm1 (SHA1), Message-Digest algorithm 5 (MD5), Cyclic redundancy check 32(CRC32), Linear Congruential Generator (LCG), or Linear-feedback shiftregister. However, the random number generation function is not limitedto the above-described functions and may include all functions capableof generating various random numbers by increasing entropy. Thefollowing equation shows a method of determining the index of the secondranging round, which is a hopped round, by using AES128.

S(i, HoppingKey, N _(Round))=(((AES(i, HoppingKey)&0xFFFF)N_(Round))»16)+1   Equation 5

The parameters of Equation 5 above may be defined to be the same as theparameters of Equation 4 described above. More specifically, S mayrepresent the index of the second ranging round that is a hopped round.i may represent the index corresponding to the second ranging block.HoppingKey may represent the hopping key described above. NRound mayrepresent the number of ranging rounds included in the ranging block.

The following equation shows a method of determining the index of thesecond ranging round, which is a hopped round, by using the SHA1function.

S(i, HoppingKey, N _(Round))=(((SHA1(i+HoppingKey)&0xFFFF)N_(Round))»16)+1   Equation 6

The parameters of Equation 6 may be defined to be the same as theparameters of Equation 4 and Equation 5 described above.

In another embodiment of the disclosure, the determining of the index ofthe second ranging round may include determining the index of the secondranging round, based on at least one of scrambled timestamp sequence(STS) code of a certain slot (reference slot) of the first ranging blockor the number of ranging rounds included in the ranging block.

More specifically, according to the present embodiment of thedisclosure, an STS of a previous block generated through AES may be usedto derive the index of the second ranging round. Because security for anindex of a hopping round is not significant, previously generated STScode may be used.

Referring to the following equation, an index of a second ranging roundfor a second ranging block with an index i may be obtained, based on STScode for a certain slot for a first ranging block with an index (i−1).

S(i, N _(Round))=(((ReferenceSlotSTS(i−1)&0xFFFF)N _(Round))»16)+1  Equation 7

Here, S represents the index of the second ranging round which is ahopped round. i may represent the index corresponding to the secondranging block. NRound may represent the number of ranging roundsincluded in the ranging block.

In an embodiment of the disclosure, when the second ranging block is ani^(th) block, the index of the first ranging block including a certainslot (reference slot) may refer to an (i−1)^(th) block. In this case,the first ranging block should be understood to mean a block foridentifying the second ranging block and thus is not determinedaccording to whether ranging succeeds or fails.

In an embodiment of the disclosure, the certain slot (reference slot)may be a first or last slot of a first block. However, the certain slotis not limited thereto and a slot in which previously generated STS codefor the first block may be used as the certain slot.

In an embodiment of the disclosure, when the first device determines toperform hopping, information about a ranging round is transmitted to thesecond device so that the first device may instruct the second device toperform hopping in the second ranging block. For example, a ranginground IE and a ranging control IE may be transmitted in a rangingcontrol message. Information about the ranging round will be describedwith reference to FIG. 13 below and the ranging control IE will bedescribed with reference to FIG. 12 below.

In operation S1040, the first device may perform ranging with the seconddevice in the second ranging round of the second ranging block. Forexample, the first device may perform ranging with the second device ina k^(th) ranging round of the second ranging block.

FIG. 11 is a table illustrating subsequent ranging rounds derived basedon a random-number generation function according to an embodiment of thedisclosure.

More specifically, referring to FIG. 11, it illustrates result valuesobtained by calculating indexes of hopping rounds by using SHA1, whichis an example of the random number generation function of thedisclosure, in operation S1030. In this case, 0xABCD was used as ahopping key HOP_Key_RW and 10 was used as the number of ranging roundsNRound included in a ranging block but embodiments are not limitedthereto. Referring to the table, when an index corresponding to a secondranging block is 1, it may be understood that a round with an index 6 isavailable as a ranging round in the second ranging block of the index 1.

Referring to FIG. 11, various indexes of hopping rounds are derivedaccording to an index i corresponding to the second ranging block. Thus,a probability of a ranging failure when a ranging round with the sameindex as another pair is used may be lowered. A more detaileddescription will be provided with reference to FIGS. 15A to 17B below.

FIG. 12 is a diagram illustrating a configuration of information aboutranging control according to an embodiment of the disclosure.

A controller may use a ranging control IE to transmit rangingconfiguration information to one controllee (in a unicast frame) or tomultiple controllees (in a broadcast frame).

Referring to FIG. 12, the ranging control IE may include a multi-nodemode field. A value of the multi-node mode field may indicate whetherranging is performed between a pair of single devices or within amulti-node range including a large number of devices.

As described above, in an embodiment of the disclosure, informationabout ranging control may include information about a configuration,such as a configuration of an advanced ranging control IE as illustratedin FIG. 12.

A ranging round usage field may specify a ranging technique and otherusages used in a ranging round.

An STS packet configuration field may specify an STS packet format to beused in a ranging round subject to the ranging control IE of FIG. 12.

A schedule mode field may specify whether ranging is performed accordingto scheduling-based ranging or contention-based ranging.

A deferred mode field may specify whether a deferred frame is allowedfor a measurement report.

A time structure indicator field may specify a ranging time structureoperation in a subsequent ranging round.

In this case, according to an embodiment of the disclosure, the timestructure indicator field may indicate whether ranging is aninterval-based ranging or block-based ranging. More specifically, when avalue of the time structure indicator field indicates a block-based timestructure, a ranging round information IE and ranging block update IEmay be used to control ranging interval updating. When the value of thetime structure indicator field indicates an internal-based timestructure, a ranging interval update IE may be used to control distanceinterval updating.

An RCM validity rounds field may specify the number of consecutiveranging rounds controlled by a ranging control message (RCM).

A multiple message receipt confirmation request (MMRCR) field mayindicate whether a multiple message reception confirmation request isneeded.

A content control field may indicate whether the ranging control IEfurther includes other fields.

A ranging block duration field may specify a ranging block duration onan RSTU basis.

A ranging round duration field may specify a ranging round period on aranging slot basis. For example, the ranging round duration field mayspecify the number of ranging slots of a ranging round.

A ranging slot duration field may specify a ranging slot duration foreach RSTU.

A session identification (ID) field may include a unique sessionidentifier for a session of each controller.

When a ranging block structure is subject to the same specified durationas before, one or more interval fields may not be included in theranging round IE. More specifically, when the specified duration remainsthe same as previously set information, a ranging round IE of a currentRCM may not include the ranging block duration field, the ranging roundduration field, and the ranging slot duration field.

However, a configuration of a ranging control IE employed in thedisclosure is not limited to that of FIG. 12 described above.

FIG. 13 is a diagram illustrating a configuration of information about aranging round according to an embodiment of the disclosure.

Referring to FIG. 13, the information about the ranging round may beused for a first device to signal ranging round information for acurrent ranging round or ranging round information for a subsequentranging round to a second device, as described above with respect tooperation S1030.

The information about the ranging round may include informationdescribed below.

The information about the ranging round may include information about acurrent ranging round (i.e., a ranging round of a ranging block i). Inthis case, the information about the ranging round may be included in aranging control message of the ranging block i. The information aboutthe ranging round, which is transmitted in the ranging control messageof the current ranging round, may be used by a device to synchronizewith a block structure. In the present specification, the currentranging round refers to a first ranging round.

The information about the ranging round may include information about asubsequent ranging round (i.e., a ranging round of a subsequent rangingblock (i+1)). For example, when a lastly scheduled message in thecurrent ranging round is a message transmitted by a controller to acontrollee, the information about the ranging round may be transmittedin this message to signal information about the ranging round of thesubsequent ranging block (i+1).

In an embodiment of the disclosure, a ranging round IE may include aranging block index field. The ranging block index field may indicate anindex of a second ranging block.

In an embodiment of the disclosure, the ranging round IE may include ahopping mode field. The hopping mode field may indicate a hopping modeof a ranging block. More specifically, the hopping mode field mayindicate a hopping mode of the second ranging block. For example, when avalue of the hopping mode is 0, it may indicate that hopping is not tobe performed, and when the value of the hopping mode is 1, it mayindicate that hopping is to be performed.

In an embodiment of the disclosure, the ranging round IE may include around index field. The round index field may indicate a ranging roundindex of the ranging block.

In an embodiment of the disclosure, the ranging round IE may include atransmission offset field. The transmission offset field may specify atransmission offset value of a ranging round in a block on an RSTUbasis. The transmission offset is a result of subtracting a packetduration from a maximum ranging slot interval.

When a second device receives information about a ranging round from afirst device, hopping may be performed, based on the information aboutthe ranging round. In this case, the first device and the second devicemay previously set a hopping sequence to be used. In the disclosure, theoperation method of FIG. 10 corresponds to a hopping sequence and thusit may be understood that the first device and the second device havepreviously set a method of determining an index of a hopping round asdescribed above. In addition, the first device and the second device mayexchange all information necessary to generate the hopping sequence.

However, a configuration of information about a ranging round employedin the disclosure is not limited to that of FIG. 13 described above.Information instructing, by the first device, the second device toperform hopping may be used as information about a ranging round.

FIG. 14 is a flowchart of an operation method of a second device whichperforms ranging by using a UWB according to an embodiment of thedisclosure. A description of parts of the operation method of FIG. 14that are the same as those of FIG. 14 is omitted here.

Referring to FIG. 14, in operation S1410, the second device may performranging with a first device in a first ranging round among a pluralityof ranging rounds included in a first ranging block.

In operation S1420, the second device may determine whether to performhopping, based on at least one of a result of performing ranging orinformation about a ranging round received from the first device.

The information about the ranging round may include at least one ofindex information of a second ranging block, index information about thesecond ranging round, or hopping mode information. The information aboutthe ranging round is as described above with reference to FIG. 13 andthus is not redundantly described here.

For example, the determining by the second device of whether to performhopping may include identifying the hopping mode information included inthe information about the ranging round. The determining, by the seconddevice, of whether to perform hopping may further include determiningwhether to perform hopping, based on the hopping mode information.

In another embodiment of the disclosure, the determining, by the seconddevice, of whether to perform hopping may include determining thathopping is to be performed when the second device does not receive aresponse from the first device in the first ranging round. In this case,for example, the message that the second device does not receive fromthe first device may be a ranging control message. Alternatively, themessage that the second device does not receive from the first devicemay include information about a ranging round.

As another example, the message that the second device does not receivefrom the first device may be a response message, from the first device,to a message transmitted from the second device.

In operation S1430, when it is determined that hopping is to beperformed, the second device may determine an index of a second ranginground for performing ranging with the first device, based on the randomnumber generation function.

In an embodiment of the disclosure, the determining by the second deviceof the index of the second ranging round may include determining theindex of the second ranging round, based on a result value of therandom-number generation function calculated based on the index of thesecond ranging block and a value of a hopping key of a ranging session.

In this case, the determining by the second device of the index of thesecond ranging round may further includes starting a ranging sessionbetween the first device and the second device and receiving by thesecond device a hopping key for the ranging session from the firstdevice.

In an embodiment of the disclosure, the random-number generationfunction may include the hash function. The second device may determinethe index of the second ranging round based on a result value of thehash function for the sum of the index of the second ranging block andthe value of the hopping key for the ranging session.

In another embodiment of the disclosure, the determining by the seconddevice of the index of the second ranging round may include determiningthe index of the second ranging round, based on at least one of STS codefor a certain slot of the first ranging block or the number of rangingrounds included in the ranging block.

A detailed description is as described above in operation S1030 of FIG.10 and thus is omitted here.

In operation S1440, the second device may perform ranging with the firstdevice in the second ranging round of the second ranging block.

FIGS. 15A to 17B are diagrams illustrating a ranging success rate whenranging is performed according to an index of a determined hopping rangeround according to various embodiments of the disclosure.

For convenience of description, a ranging session is established by thefirst device and the second device and thus the first and second devicesmay be defined as a first pair. In addition, a ranging session isestablished by a third device and a fourth device and thus the third andfourth devices may be defined as a second pair.

For convenience of description, a second ranging round, which refers toa ranging round used when it is determined that hopping is to beperformed, will be defined and described below as a hopping round.

FIGS. 15A and 15B are diagrams illustrating a ranging success rate foreach ranging block when it is assumed that a hopping key with a fixedvalue of 1 is allocated to a first pair and a second pair according tovarious embodiments of the disclosure.

In order to obtain a success rate, 1000 iterations were performed. Inthis case, a ranging start time of each of the first pair and the secondpair or a round at which ranging is started was randomly set at eachiteration. FIG. 15A illustrates a ranging success rate when an index ofa hopping round obtained according to the related art was used. FIG. 15Aillustrates a ranging success rate when an index of a hopping roundobtained according to an embodiment of the disclosure was used.

Referring to FIG. 15A, when an index of a hopping round was obtainedaccording to the related art, a success rate was 20% with respect to ablock with an index of 2 and was 50% with respect to a block with anindex of 4. This means that ranging rounds of the first pair and thesecond pair may be set to overlap for several blocks and thus aprobability that each of the first pair and the second pair will besuccessful in terms of ranging is low. For example, it means thathopping rounds obtained by performing hopping by the first pair andranging rounds used by the second pair may consecutively overlap. As avalue of a block increases, a success rate increases. This may beunderstood to mean that a probability that indexes of hopping roundsused by the first pair and the second pair will continuously overlapdecreases and decreases as an index of a block increases.

Referring to FIG. 15B, when an index of a hopping round was obtainedaccording to an embodiment of the disclosure, a success rate was about96% with respect to a block with an index of 1 and was 100% with respectto a block with an index of 2. Referring to FIG. 11, this is an effectoccurring because, when indexes of hopping round are obtained accordingto an embodiment of the disclosure, various indexes of the hopping roundmay be derived for blocks. For example, various indexes of a hoppinground may be generated for blocks by the first pair. Similarly, variousindexes of a hopping round may be generated for blocks by the secondpair and thus a probability that indexes of the hopping round generatedby the first pair and indexes of the hopping round generated by thesecond pair will overlap is extremely low, thereby achieving a rangingsuccess rate within a short time.

FIGS. 16A and 16B show results similar to those of FIGS. 15A and 15Bdescribed above.

FIGS. 16A and 16B are diagrams illustrating a ranging success rate foreach ranging block when it is assumed that the same hopping key isallocated to a first pair and a second pair according to variousembodiments of the disclosure.

To obtain a success rate, 100 hopping keys were used. In addition, 10iterations were performed for each given key. In this case, a rangingstart time of each of the first pair and the second pair or a round atwhich ranging is started was randomly set at each iteration. FIG. 16Aillustrates a ranging success rate when an index of a hopping roundobtained according to the related art was used. FIG. 16B illustrates aranging success rate when an index of a hopping round obtained accordingto an embodiment of the disclosure was used.

Referring to FIG. 16A, when an index of a hopping round was obtainedaccording to the related art, a success rate was 60% with respect to ablock with an index of 2 and was about 88% with respect to a block withan index of 4.

Referring to FIG. 16B, when an index of a hopping round was obtainedaccording to an embodiment of the disclosure, a success rate was about98% with respect to a block with an index of 1 and was 100% with respectto a block with an index of 2.

FIGS. 17A and 17B show results similar to those of FIGS. 15A, 15B, 16Aand 16B described above.

FIGS. 17A and 17B are a diagram illustrating a ranging success rate foreach ranging block when it is assumed that different hopping keys areallocated to a first pair and a second pair according to variousembodiments of the disclosure. To obtain a success rate, 100 randomhopping keys were used. In addition, 10 iterations were performed foreach given key. In this case, a ranging start time of each of the firstpair and the second pair or a round at which ranging is started wasrandomly set at each iteration. FIG. 17A illustrates a ranging successrate when an index of a hopping round obtained according to the relatedart was used. FIG. 17B illustrates a ranging success rate when an indexof a hopping round obtained according to an embodiment of the disclosurewas used.

Referring to FIG. 17A, when an index of a hopping round was obtainedaccording to the related art, a success rate was 96% with respect to ablock with an index of 1 and was 100% with respect to a block with anindex of 1.

Referring to FIG. 17B, when an index of a hopping round was obtainedaccording to an embodiment of the disclosure, a success rate was about97% with respect to a block with an index of 1 and was 100% with respectto a block with an index of 3.

When taken into consideration of FIGS. 11 and 15A to 17B, a probabilityof ranging failure caused when the same ranging round is used by eachpair may be greatly reduced by using a hopping sequence for obtaining anindex of a hopping ranging round according to an embodiment of thedisclosure. This is because various indexes of a hopping ranging roundmay be obtained by increasing entropy as illustrated in FIG. 11.Accordingly, according to an embodiment of the disclosure, a probabilitythat a pattern of an index of a hopping ranging round will be repeatedgenerated for each block is extremely low. Furthermore, according to anembodiment of the disclosure, indexes of hopping ranging roundsgenerated by pairs do not continuously overlap for several rangingblocks. Therefore, it is possible to increase a probability that eachpair will succeed in ranging.

FIG. 18 is a block diagram of a controller 100 according to anembodiment of the disclosure.

In an embodiment of the disclosure, the controller 100 may be a fixeduser terminal (UE) or a mobile UE. Examples of the controller 100 mayinclude, but are not limited to, at least one of a smart phone, acellular phone, a navigation device, a computer, a laptop computer, adigital broadcasting terminal, an artificial intelligence speaker, aspeaker, a personal digital assistant (PDA), a portable multimediaplayer (PMP), or a tablet PC. The controller 100 may communicate withother devices and/or servers via a network by using a wireless or wiredcommunication method.

Referring to FIG. 18, the controller 100 according to an embodiment ofthe disclosure may include a communicator 110, a processor 120, and amemory 130. However, the controller 100 may be embodied as includingmore components than all the components illustrated in FIG. 18. Forexample, as illustrated in FIG. 20, the controller 100 according to anembodiment of the disclosure may include at least one of a user inputdevice 1100, an output device 1200, a detector 1400 or an audio/video(A/V) input device 1600.

Although the controller 100 is illustrated as including one processor inFIG. 18, embodiments of the disclosure are not limited thereto and thecontroller 100 may include a plurality of processors. At least some ofoperations and functions of the processor 120 described below may beperformed by a plurality of processors. The controller 100 illustratedin FIG. 18 may perform operation methods of the controller 100 accordingto various embodiments of the disclosure, and the descriptions of FIGS.3 to 17B may apply thereto. Therefore, a description of the controller100 that is the same as those of FIGS. 3 and 17B described above isomitted here.

The communicator 110 according to an embodiment of the disclosure mayestablish wired or wireless communication with other devices via anetwork. To this end, the communicator 110 may include a communicationmodule supporting at least one of various wired and wirelesscommunication methods. For example, the communication module may be inthe form of a chipset or may be a sticker/barcode (e.g., a sticker witha near-field communication (NFC) tag) storing information necessary forcommunication.

The wireless communication may include, for example, at least one ofcellular communication, wireless fidelity (Wi-Fi), Wi-Fi Direct,Bluetooth, UWB, or near-field communication (NFC). The wiredcommunication may include, for example, at least one of USB orhigh-definition multimedia interface (HDMI).

In an embodiment of the disclosure, the communicator 110 may include acommunication module for short range communication. For example, thecommunicator 110 may include a communication module for establishingvarious short-range communications, such as infrared communication andmagnetic secure transmission (MST) communication, as well as UWB, Wi-Fi,Wi-Fi Direct, Bluetooth, and NFC described above.

The processor 120 according to an embodiment of the disclosure controlsoverall operations of the controller 100 and may include at least oneprocessor, such as a central processing unit (CPU) or a graphicalprocessing unit (GPU). The processor 120 may control other componentsincluded in the controller 100 to perform UWB ranging. The memory 130may store a program for processing and controlling performed by theprocessor 120, and store data input to or output from the controller100.

In an embodiment of the disclosure, the processor 120 may performranging with a second device in a first ranging round among a pluralityof ranging rounds included in a first ranging block.

In an embodiment of the disclosure, the processor 120 may determinewhether to perform hopping, based on a result of performing ranging. Forexample, the processor 120 may determine to perform hopping when a firstdevice did not receive a response from the second device in the firstranging round. As another example, the processor 120 may determine toperform hopping based on an interference level for the first ranginground.

In an embodiment of the disclosure, when it is determined that hoppingis to be performed, the processor 120 may determine an index of a secondranging round for performing ranging with the second device, based onthe random-number generation function. For example, the processor 120may determine the index of the second ranging round by considering aresult value of the random-number generation function calculated basedon an index of a second ranging block and a hopping key value for aranging session. The random-number generation function may include thehash function, and the processor 120 may determine the index of thesecond ranging round based on a result value of the hash function forthe sum of the index of the second ranging block and the hopping keyvalue for the ranging session. In addition, the processor 120 may starta ranging session between the first device and the second device andtransmit a hopping key for the ranging session.

In an embodiment of the disclosure, the processor 120 may determine theindex of the second ranging round, based on at least one of STS code fora certain slot of the first ranging block or the number of rangingrounds included in a ranging block.

In an embodiment of the disclosure, when it is determined that hoppingis to be performed, the processor 120 may transmit information about aranging round to the second device to instruct to perform hopping in thesecond ranging block.

In an embodiment of the disclosure, the processor 120 may performranging with the second device in a second ranging round of the secondranging block. In this case, an index of the first ranging round and anindex of the second ranging round may be different values.

The above description with respect to FIGS. 3 to 17B may apply to amethod for a hopping sequence, the method being performed by theprocessor 120 and thus is omitted herein.

FIG. 19 is a block diagram of a controllee 200 according to anembodiment of the disclosure.

In an embodiment of the disclosure, the controllee 200 may be a fixed UEor a mobile UE. Examples of the controllee 200 may include, but are notlimited to, at least one of a smart phone, a cellular phone, anavigation device, a computer, a laptop computer, a digital broadcastingterminal, an artificial intelligence speaker, a speaker, a personaldigital assistant (PDA), a portable multimedia player (PMP), or a tabletPC. The controllee 200 may communicate with other devices and/or serversvia a network by using a wireless or wired communication method.

Referring to FIG. 19, the controllee 100 according to an embodiment ofthe disclosure may include a communicator 210, a processor 220, and amemory 230. However, the controllee 200 may be embodied as includingmore components than all the components illustrated in FIG. 19. Forexample, as illustrated in FIG. 20, according to some embodiments of thedisclosure, the controllee 200 may include at least one of a user inputdevice 1100, an output device 1200, a detector 1400, or an audio/video(A/V) input device 1600.

Although the controllee 200 is illustrated as including one processor inFIG. 19, embodiments of the disclosure are not limited thereto and thecontrollee 200 may include a plurality of processors. At least some ofoperations and functions of the processor 220 described below may beperformed by a plurality of processors. The controllee 200 illustratedin FIG. 19 may perform operation methods according to variousembodiments of the disclosure and the descriptions of FIGS. 3 to 17B mayapply thereto. Therefore, a description of the controllee 200 that isthe same as those of FIGS. 3 and 17B described above is omitted here.

The communicator 210 according to an embodiment of the disclosure mayestablish wired or wireless communication with other devices via anetwork. To this end, the communicator 210 may include a communicationmodule supporting at least one of various wired and wirelesscommunication methods. For example, the communication module may be inthe form of a chipset or may be a sticker/barcode (e.g., a sticker withan NFC tag) storing information necessary for communication.

The wireless communication may include, for example, at least one ofcellular communication, Wi-Fi, Wi-Fi Direct, Bluetooth, UWB, or NFC. Thewired communication may include, for example, at least one of USB orhigh-definition multimedia interface (HDMI).

In an embodiment of the disclosure, the communicator 210 may include acommunication module for short range communication. For example, thecommunicator 210 may include a communication module for establishingvarious short-range communications, such as infrared communication andmagnetic secure transmission (MST) communication, as well as UWB, Wi-Fi,Wi-Fi Direct, Bluetooth, and NFC described above.

The processor 120 according to an embodiment of the disclosure controlsoverall operations of the controllee 200 and may include at least oneprocessor, such as a CPU or a GPU. The processor 220 may control othercomponents included in the controllee 200 to perform UWB ranging. Thememory 230 may store a program for processing and controlling performedby the processor 220, and store data input to or output from thecontrollee 200.

In an embodiment of the disclosure, the processor 220 may performranging with a first device in a first ranging round among a pluralityof ranging rounds included in a first ranging block.

In an embodiment of the disclosure, the processor 120 may determinewhether to perform hopping, based on at least one of a result ofperforming ranging or information about a ranging round received fromthe first device.

In an embodiment of the disclosure, the information about the ranginground may include at least one of index information of the secondranging block, index information about the second ranging round, orhopping mode information. The processor 220 may identify the hoppingmode information included in the information about the ranging round,and determine whether to perform hopping, based on the hopping modeinformation.

As another example, the processor 220 may determine to perform hoppingwhen a second device did not receive a response from the first device inthe first ranging round.

In an embodiment of the disclosure, when it is determined that hoppingis to be performed, the processor 220 may determine an index of a secondranging round for performing ranging with the first device, based on therandom-number generation function.

For example, the processor 220 may determine the index of the secondranging round by considering a result value of the random-numbergeneration function calculated based on an index of a second rangingblock and a value of a hopping key for a ranging session.

The processor 220 may start a ranging session between the first deviceand the second device, and the second device may receive the hopping keyfor the ranging session from the first device.

In an embodiment of the disclosure, the processor 120 may performranging with the first device in a second ranging round of the secondranging block. An index of the first ranging round and an index of thesecond ranging round may be different values.

The above description with reference to FIGS. 3 to 17B may apply to adetailed method for a hopping sequence, the method being performed bythe processor 220, and thus is omitted here.

FIG. 20 is a block diagram of an electronic device according to anembodiment of the disclosure.

Referring to FIG. 20, a device 1000 may include the same components asthe controller 100 of FIG. 18 and the controlee 200 of FIG. 19. Forexample, a controller 1300 among components illustrated in FIG. 20 maybe the same as the processor 120 illustrated in FIG. 18 or the processor220 illustrated in FIG. 19. A communicator 1500 among the componentsillustrated in FIG. 20 may be the same as the communicator 110illustrated in FIG. 18 or the communicator 210 illustrated in FIG. 19. Amemory 1700 among the components illustrated in FIG. 20 may be the sameas the memory 130 illustrated in FIG. 18 or the memory 230 illustratedin FIG. 19.

The device 1000 of FIG. 20 may perform all the operations and functionsof the controller 100 or the controllee 200 described above. Therefore,components of the device 1000 that are not described above will bedescribed below.

Referring to FIG. 20, the device 1000 may include the user input device1100, the output device 1200, the controller 1300, the detector 1400,the communicator 1500, the A/V input device 1600, and the memory 1700.

The user input device 1100 refers to a means for inputting data by auser to control the device 1000. Examples of the user input device 1100may include, but are not limited to, a key pad, a dome switch, a touchpad (a touch-type capacitive touch pad, a pressure-type resistiveoverlay touch pad, an infrared sensor-type touch pad, a surface acousticwave conduction touch pad, an integration-type tension measurement touchpad, a piezo effect-type touch pad, or the like), a jog wheel, a jogswitch, or the like. The user input device 1100 may receive a user inputnecessary for generating conversation information to be provided to auser.

The output device 1200 may output an audio signal, a video signal, or avibration signal, and include a display 1210, a sound output device1220, and a vibration motor 1230. The output device 1200 according to anembodiment of the disclosure may notify a user that the device 1000 isin a high attenuation situation. For example, the output device 1200 mayinduce the device 1000 to be taken out of the user's pocket for accurateranging.

The vibration motor 1230 may output a vibration signal. For example, thevibration motor 1230 may output a vibration signal corresponding to anoutput of audio data or video data (e.g., call signal reception sound,message reception sound, or the like).

The detector 1400 may detect a state of the device 1000 or surroundingconditions of the device 1000 and transmit detected information to thecontroller 1300.

The detector 1400 may include, but is not limited to, at least one of ageomagnetic sensor 1410, an acceleration sensor 1420, atemperature/humidity sensor 1430, an infrared sensor 1440, a gyroscopesensor 1450, a position sensor (e.g., a geographic positioning system(GPS)) 1460, an air pressure sensor 1470, a proximity sensor 1480, or ared green blue (RGB) sensor (illuminance sensor) 1490.

The detector 1400 according to an embodiment of the disclosure maydetect a movement of the device 1000. The controller 1300 may reduce atransmission interval of an initial connection message when a movementof the device 1000 is sensed, and increase the transmission interval ofthe initial connection message when a movement of the device 1000 is notdetected for a certain time. Functions of these sensors are intuitivelyreasonable by those of ordinary skill in the art from the names thereofand thus a detailed description thereof is omitted here.

The communicator 1500 may include a component for communication withother devices. For example, the communicator 1500 may include ashort-range wireless communicator 1510, a mobile communicator 1520, anda broadcast receiver 1530.

The short-range wireless communicator 1510 may include, but is notlimited to, a Bluetooth communicator, a Bluetooth low energy (BLE)communicator, a near-field communicator, a WLAN (Wi-Fi) communicator, aZigBee communicator, an infrared data association (IrDA) communicator, aWFD (Wi-Fi Direct) communicator, an ultra-wideband (UWB) communicator,an Ant+ communicator, and the like.

The mobile communicator 1520 transmits a radio signal to or receives aradio signal from at least one of a base station, an external UE, or aserver via a mobile communication network. Here, the radio signal mayinclude a voice call signal, a video call signal, or various types ofdata according to transmission or reception a text/multimedia message.

The broadcast receiver 1530 receives a broadcast signal and/orbroadcast-related information from the outside through a broadcastchannel The broadcast channel may include a satellite channel and aterrestrial channel According to an embodiment of the disclosure, thedevice 1000 may not include the broadcast receiver 1530.

The AN input device 1600 is configured to input an audio signal or avideo signal, and may include a camera 1610 and a microphone 1620. Thecamera 1610 may obtain a video frame, such as a still image or a movingpicture, through an image sensor in a video call mode or a shootingmode. An image captured by the image sensor may be processed by thecontroller 1300 or a separate image processor (not shown).

An image frame processed by the camera 1610 may be stored in the memory1700 or transmitted to the outside through the communicator 1500. Two ormore cameras 1610 may be provided according to an embodiment of a UE.

The microphone 1620 receives an external sound signal and converts theexternal sound signal into electrical voice data. For example, themicrophone 1620 may receive a sound signal from an external device or aspeaker. The microphone 1620 may use various noise removing algorithmsto remove noise generated during receiving an external sound signal.

The memory 1700 may store a program for processing and controlling thecontroller 1300, and store data input to or output from the device 1000.

The memory 1700 may include at least one type of storage medium among aflash memory type storage medium, a hard disk type storage medium, amultimedia card micro type storage medium, a card type memory (e.g., SDor XD memory), RAM, SRAM, ROM, EEPROM, PROM, magnetic memory, a magneticdisk, and an optical disk.

Programs stored in the memory 1700 may be classified into a plurality ofmodules, e.g., a user interface (UI) module 1710, a touch screen module1720, a notification module 1730, and the like, according to functionsthereof

The UI module 1710 may provide a specialized UI, a graphical userinterface (GUI), or the like, which is linked to the device 1000 foreach application. The touch screen module 1720 may detect a user's touchgesture on a touch screen and transmit information about the touchgesture to the controller 1300. The touch screen module 1720 accordingto some embodiments of the disclosure may identify and analyze touchcode. The touch screen module 1720 may be configured as separatehardware, including a controller.

The notification module 1730 may generate a signal for notifying theoccurrence of an event of the device 1000. Examples of events occurringin the device 1000 include call signal reception, message reception, keysignal input, schedule notification, and the like.

The embodiments of the disclosure set forth herein may be implemented asa software (S/W) program including instructions stored in acomputer-readable storage medium.

The computer refers to a device capable of calling an instruction storedin a storage medium and operating according to the called instructionaccording to the embodiments of the disclosure set forth herein, and mayinclude an image transmission device and an image receiving deviceaccording to the embodiments of the disclosure set forth herein.

The computer-readable storage medium may be provided as a non-transitorystorage medium. Here, the term ‘non-transitory storage medium’ should beunderstood to mean a tangible device and to not include a signal (e.g.,electromagnetic waves) but is not intended to distinguish between a casein which data is semi-permanently stored in the storage medium and acase in which data is temporarily stored in the storage medium. Forexample, the ‘non-transitory storage medium’ may include a buffer inwhich data is temporarily stored.

Electronic devices or methods according to the embodiments of thedisclosure set forth herein may be provided by being included in acomputer program product. A computer program product may be traded as aproduct between a seller and a purchaser.

The computer program product may include an S/W program and acomputer-readable storage medium storing the S/W program. For example,the computer program product may include a product (e.g., a downloadableapplication) in the form of an S/W program distributed electronically bythe manufacturer of an electronic device or through an electronic market(e.g., Google Play Store or App Store). For electronic distribution ofthe computer program product, at least part of the S/W program may bestored in a storage medium or temporarily generated. In this case, thestorage medium may be a storage medium of a server of the manufacturer,a server of the electronic market, or a storage medium of a relay serverthat temporarily stores the S/W program.

The computer program product may include a storage medium of a server ora storage medium of a UE in a system consisting of the server and the UE(e.g., an image transmitting device or an image receiving device).Alternatively, when there is a third device (e.g., a smart phone)capable of establishing communication with the server or the UE, thecomputer program product may include a storage medium of the thirddevice. Alternatively, the computer program product may include a S/Wprogram transmitted from the server to the UE or the third device ortransmitted from the third device to the UE.

In this case, the server, the UE, or the third device may execute thecomputer program product to perform the methods according to theembodiments of the disclosure set forth herein. Alternatively, two ormore among the server, the UE, and the third device may execute thecomputer program product to the methods according to the embodiments ofthe disclosure set forth herein in a distributed manner.

For example, the server (e.g., a cloud server or an artificialintelligence server) may execute the computer program product stored inthe server to control the UE connected thereto through communication toperform the methods according to the embodiments of the disclosure setforth herein.

As another example, the third device may execute the computer programproduct to control the UE connected thereto to perform the methodsaccording to the embodiments of the disclosure set forth herein. As aconcrete example, the third device may remotely control an imagetransmitting device or an image receiving device to transmit or receivea packing image.

When the third device executes the computer program product, the thirddevice may download the computer program product from the server andexecute the downloaded computer program product. Alternatively, thethird device may execute the computer program product provided in apreloaded state to perform the methods according to the embodiments ofthe disclosure set forth herein.

While the disclosure has been shown and described with reference tovarious embodiments thereof, it will be understood by those skilled inthe art that various changes in form and details may be made thereinwithout departing from the spirit and scope of the disclosure as definedby the appended claims and their equivalents.

What is claimed is:
 1. A method of operating a first device whichperforms ranging by using an ultra-wide band (UWB), the methodcomprising: performing ranging with a second device in a first ranginground among a plurality of ranging rounds included in a first rangingblock; determining whether to perform hopping, based on a result of theperforming of the ranging; when it is determined to perform the hopping,determining an index of a second ranging round for performing theranging with the second device, based on a random-number generationfunction; and performing the ranging with the second device in thesecond ranging round of a second ranging block, wherein an index of thefirst ranging round and the index of the second ranging round aredifferent values.
 2. The method of claim 1, wherein the determining ofthe index of the second ranging round comprises determining the index ofthe second ranging round, based on a result value of the random-numbergeneration function determined based on an index of the second rangingblock and a value of a hopping key for a ranging session.
 3. The methodof claim 2, wherein the random-number generation function comprises ahash function, and wherein the determining of the index of the secondranging round comprises determining the index of the second ranginground, based on a result value of the hash function for a sum of theindex of the second ranging block and the value of the hopping key forthe ranging session.
 4. The method of claim 2, wherein the random-numbergeneration function comprises at least one of Advanced EncryptionStandard 128, Secure Hash Algorithm 1, Message-Digest algorithm 5,Cyclic redundancy check 32, Linear congruential generator, orlinear-feedback shift register.
 5. The method of claim 2, furthercomprising transmitting, by the first device, the hopping key for theranging session.
 6. The method of claim 1, wherein the determining ofthe index of the second ranging round comprises determining the index ofthe second ranging round, based on at least one of a scrambled timestampsequence (STS) code for a certain slot of the first ranging block or thenumber of ranging rounds included in a ranging block.
 7. The method ofclaim 1, further comprising, when it is determined to perform hopping,transmitting information about a ranging round to the second device soas to instruct to perform hopping in the second ranging block.
 8. Themethod of claim 1, wherein the determining of whether to perform thehopping, based on the result of the performing of the ranging, comprisesdetermining, by the first device, that the hopping is to be performedwhen a response is not received from the second device in the firstranging round.
 9. The method of claim 1, wherein the determining ofwhether to perform the hopping, based on the result of the performing ofthe ranging, comprises determining to perform the hopping, based on aninterference level for the first ranging round.
 10. A method ofoperating a second device which performs ranging by using an ultra-wideband (UWB), the method comprising: performing ranging with a firstdevice in a first ranging round among a plurality of ranging roundsincluded in a first ranging block; determining whether to performhopping, based on at least one of a result of the performing of theranging or information about a ranging round received from the firstdevice; when it is determined to perform the hopping, determining anindex of a second ranging round for performing ranging with the firstdevice, based on a random-number generation function; and performingranging with the first device in the second ranging round of a secondranging block, wherein an index of the first ranging round and the indexof the second ranging round are different values.
 11. The method ofclaim 10, wherein the determining of the index of the second ranginground comprises determining the index of the second ranging round, basedon a result value of the random-number generation function determinedbased on an index of the second ranging block and a value of a hoppingkey for a ranging session.
 12. The method of claim 11, wherein therandom-number generation function comprises at least one of AdvancedEncryption Standard 128, Secure Hash Algorithm 1, Message-Digestalgorithm 5, Cyclic redundancy check 32, Linear congruential generator,or linear-feedback shift register.
 13. The method of claim 11, furthercomprising receiving, by the second device, the hopping key for theranging session from the first device.
 14. The method of claim 11,wherein the information about the ranging round comprises at least oneof index information of the second ranging round, or hopping modeinformation.
 15. The method of claim 14, wherein the determining ofwhether to perform the hopping comprises: identifying the hopping modeinformation included in the information about the ranging round; anddetermining whether to perform the hopping, based on the hopping modeinformation.
 16. The method of claim 11, wherein the determining ofwhether to perform the hopping comprises determining, by the seconddevice, that hopping is to be performed when a response is not receivedfrom the first device in the first ranging round.
 17. A first devicewhich performs ranging by using an ultra-wide band (UWB), the firstdevice comprising: a communicator; a memory; and at least one processorconfigured to: execute a program stored in the memory to controloperations of the first device, perform ranging with a second device ina first ranging round among a plurality of ranging rounds included in afirst ranging block, determine whether to perform hopping, based on aresult of the performing of the ranging, when it is determined toperform the hopping, determine an index of a second ranging round forperforming ranging with a second device, based on a random-numbergeneration function, and perform ranging with the second device in thesecond ranging round of a second ranging block, wherein an index of thefirst ranging round and the index of the second ranging round aredifferent values.
 18. The first device of claim 17, wherein the at leastone processor is further configured to determine the index of the secondranging round, based on a result value of the random-number generationfunction determined based on an index of the second ranging block and avalue of a hopping key for a ranging session.
 19. The first device ofclaim 17, wherein the random-number generation function comprises atleast one of Advanced Encryption Standard 128, Secure Hash Algorithm 1,Message-Digest algorithm 5, Cyclic redundancy check 32, Linearcongruential generator, or linear-feedback shift register.
 20. The firstdevice of claim 17, wherein the at least one processor is furtherconfigured to transmit information about a ranging round to the seconddevice so as to instruct to perform hopping in the second ranging block,when it is determined to perform hopping.